Today, the alternative class vehicles left in the competition are running a 90-mile efficiency test to determine the all-important miles per gallon equivalent (mpge) number (tomorrow, the mainstream class vehicles will run a similar 200-mile test). As most anyone who's heard of the X-Prize knows, the marquee goal here is 100 mpge, which is not an easy target. The way the team's final mpge value will be calculated is by taking today's drive result and adding it to the mpge figure that the cars get when they are tested in the Argonne National Lab in the coming weeks (and then divide by two, of course). In order to make it to the lab, though, the teams will need to reach at least 90 mpge today Breaking into the triple digits just gives them some well-earned breathing room.
On Tuesday, all the cars will run a combined performance and efficiency test over 100 miles, but the only important number that will be determined there is the overall time, which is the tiebreaker for placement. Don't think the teams can just floor it during this portion of the event, since there will be penalties for dropping below 100 mpge.